My 12 year stealth account has a landline phone number in my real name not stealth name. First, will I get a code via landline since they can't text me on it and second, will I fail since the names won't match?

They cannot see the name of the phone number holder.
And no you cannot get an SMS code over a landline obviously and in many cases that's the only kind of verification theyll permit.
Maybe consider adding another phone number to the account - a mobile one. No need to remove your other phone number.

You can add a google voice number or prepaid cell & you probably won’t have any problems. But adding a cell phone from a major carrier would be best. And it may take a bit (sometimes months) before that new number will show up as an option in the security check.